1. Field of the Invention
The present invention relates to an arrangement of boards, wirings and connectors in an image forming apparatus such as printer, multifunction peripheral etc.
2. Description of the Related Art
An arrangement of the components in the conventional general image forming apparatus is described with reference to FIG. 6. FIG. 6 is a diagram illustrating the image forming apparatus when viewed from a back side of a main body. In FIG. 6, broken lines show components, which are invisible from the back side of the main body. Such components include photoreceptor drums 404, developing devices 405, an intermediate transfer belt 401, a laser exposure device 408, primary transfer roller 414, a fixing device 450, a sheet feeding cassette 421, a delivery tray 425, toner bottles 430Y, 430M, 430C, 430K and the like.
On the back side of the image forming apparatus, an image control board 503, connected to a user interface for controlling an image forming process, is arranged, when viewed from the back side, at an upper left part. A load control board 501 is arranged at an upper right part when viewed from the back side of the image forming apparatus in parallel with the image control board 503. The load control board 501 is used to control driving system load components and sensors of the image forming apparatus. A power source board 502 is arranged at a lower part when viewed from the back side. The power source board 502 is to distribute AC power supplied from a commercial power supply, or to convert the AC power into DC power. High voltage boards 504 and 505 are arranged near the photoreceptor drum 404 and the developing device 405. Motors 515 and 516 are arranged side by side with the high voltage board 504. The motors 515 and 516 are to drive the photoreceptor drum 404 and a screw in the developing device 405. Conveyance driving motors 512 and 513 are arranged near a recording paper conveyance path. The conveyance driving motors 512 and 513 are to drive rollers for conveying a recording paper from the sheet feeding cassettes 421.
The load control board 501 supplies control signal and power to the load components such as motors and each board. In U.S. Pat. No. 7,599,638B2, a board corresponding to a load control board is separated into two boards. The separated boards are arranged inside and outside by sandwiching a main body frame of an image forming apparatus in between to downsize the image forming apparatus.
Providing a simple structure by decreasing the length of wiring as much as possible is effective for reducing troubles relating to wiring such as a short circuit when assembling the image forming apparatus or when exchanging parts. It is also effective for reducing costs.
In the conventional image forming apparatus as shown in FIG. 6, the load control board 501 is arranged away from the respective load components and boards. Therefore, wirings for communicating control signal and wirings for supplying power are diagonally arranged on the back side of the main body. This increases the wiring length and costs. Also, there may increase a risk of a wiring short circuit when assembling or exchanging parts.
According to the image forming apparatus as described in U.S. Pat. No. 7,599,638B2, downsizing of the image forming apparatus is achieved, however, further improvement is still required for wiring.